spi/rspi: Add missing dependency on DMAE

The filter function used by the rspi driver is part of the DMAE controller
driver so if the DMA controller driver is somehow disabled then the rspi
driver will fail to build.

Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 89cbbab..175491f 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -341,7 +341,7 @@
 
 config SPI_RSPI
 	tristate "Renesas RSPI controller"
-	depends on SUPERH
+	depends on SUPERH && SH_DMAE_BASE
 	help
 	  SPI driver for Renesas RSPI blocks.